Archive for the ‘Carpinteria Salt Marsh’ Category

The Case of the Twisted Stem

Sunday, October 16th, 2011

Yesterday Linda and I took a brief hike on the Jesusita Trail in Santa Barbara. The area we were walking through was burned in a 2009 wildfire, but it has mostly recovered now. Still, there are signs of the fire — blackened stumps and twigs — if you look for them. There is also a fair amount of coyote brush (Baccharis pilularis), so naturally that ended up being the focus of my attention.

I was surprised to see that there were no Rhopalomyia californica bud galls on any of the plants. I’m not sure why that is. Maybe it’s a legacy of the fire, with the gall midges taking a while to reestablish themselves. Or maybe this is typical of coyote brush stands higher up in the foothills. The Jesusita trailhead is more than three miles inland, while most of my experience with coyote brush has been at the salt marsh and the Carpinteria bluffs, right next to the ocean. Maybe R. californica is more of a coastal species?

At one point I was looking at a spindly clump of burned stems emerging from the center of an otherwise-green coyote brush, when I realized that the exposed stems had the characteristic thickening of the twisted stem gall midge, Rhopalomyia baccharis. I broke off a few of the galls and brought them home for closer examination. Here they are in my hand, to give you a sense of scale:

If you look closely at this shot, you can see the elliptical openings through which the adult midges emerge:

I think these twisted stem galls are fascinating, and I’m always looking for them, but whether it’s that they’re actually rarer, or just that they’re harder to spot in the foliage, I almost never find them. I come across dozens of terminal bud galls for every twisted stem gall I find.

Back in February I found a coyote brush at the Carpinteria salt marsh that had a lot of twisted stem galls; eight or nine at least. I was excited by the find, but I was also in something of a hurry, so I just snapped a few quick photos, intending to come back later and investigate in more detail. Here are some of the shots I got:

The next chance I had to visit the marsh was a few weeks later. I assumed I’d be able to find the plant quickly (the galls gave it a distinctive, gnarled appearance), but I ran out of time without finding it. By the time I could get back to the marsh for a more thorough search it was early April. Even looking more carefully, though, I couldn’t locate the plant. One was in the right spot, but it was much smaller than the plant I remembered, and had no visible galls, so I dismissed it quickly.

Where were the stem galls? I really had seen them; I had photos to prove it. But now they just weren’t there. I wandered back to the center of my search pattern, next to the small coyote brush, and stood there scowling.

And happened to take a closer look at the plant:


I suddenly remembered a conversation I’d had recently with Andrea, the head of the docent program, about some new workers hired by the city, with whom she’d had words about their over-zealous pruning of the native plants. The workers had seen the coyote brush with its noticeably gnarled stems, and had done what any self-respecting gardener would do: They’d pruned away the damaged branches.

Sigh. My quest for twisted stem galls continues.

Chaparral Mallow in Bloom at the Carpinteria Salt Marsh

Tuesday, July 26th, 2011

If you haven’t been to the Carpinteria salt marsh in a while, this is a great time to visit. The chaparral mallow (Malacothamnus fasciculatus) is in bloom, making the walk to the amphitheater a fairly surreal experience:

I traded docent shifts with Rob Denholtz this month, so I was there on the third Saturday in July, rather than my usual second Saturday. No one showed up for the tour, though, so I took a stroll through the marsh myself, and was rewarded by a breathtaking profusion of purple flowers.

I’m on record as having a crush on coyote brush (Baccharis pilularis). Linda attended a recent talk by Carol Bornstein, author of Reimagining the California Lawn, and Linda told me coyote brush was among the plants Bornstein discussed.

Bornstein wrote in her book about coyote brush’s “utilitarian” character, and Linda said she called it “fairly drab” during her talk, which of course makes me want to rise to its defense. But I admit that its flowers are not the showiest.

Chaparral mallow is another story. If I have a crush on coyote brush, I felt a temporary transfer of affections to chaparral mallow as I walked past the wall of flowers at the marsh. You really should visit while they’re in bloom.

Invertebrate Tracks in the Coastal Dune Habitat

Sunday, October 3rd, 2010

I like being a volunteer docent at the Carpinteria Salt Marsh Nature Park, but it’s also pretty fun when no one shows up and I get to give myself a tour. That’s what happened yesterday.

I noticed some interesting tracks by the boardwalk in the coastal dune habitat. I suspect this collapsed tunnel is from a globose dune beetle (Coelus globosus):

I’m curious what made this trail winding its way down (or up?) this slope:

It reminds me a little of a millipede trail, like this (much larger) trail from 300 million years ago, or this video of a modern millipede leaving its tracks in the sand.

I don’t have any particularly good idea what made this trail. I think I might be seeing a double line, possibly with three sets of footprints outside them:

I previously corresponded with Charley Eiseman (co-author of Tracks & Signs of Insects and Other Invertebrates) about how neat it would be if there was a site like, but focused on tracks and signs. I’m thinking of taking that on; it sounds like it would not be too difficult to set up such a site using Drupal, which I gather is the tool they used to create I’m not sure I want to take on another project, but it would be awfully neat to have access to a site like that.

Bolas spider (Mastophora cornigera)

Saturday, December 12th, 2009

Last Saturday I was able to bird the “middle” portion of the Carpinteria salt marsh (normally inaccessible to outside visitors). Even better, I got to go in with Peter Gaede and Andrea Adams-Morden, two of my favorite people when I want to learn more about birds or plants (respectively). That’s damning with faint praise, though, in that Peter and Andrea are just fun to be with. They’re interested in everything going on in the natural world, always noticing things and always happy to share what they’ve noticed.

We entered on Estero Way, and worked our way out to the mouth of the marsh. Then we retraced our steps, and wrapped around next to the railroad tracks until we could walk out along the dike on the west side of the Santa Monica Creek channel. Toward the southern end of the dike there is a large patch of an invasive non-native with tall spindly stalks; Andrea tentatively ID’d it as black mustard (Brassica nigra). Here’s a shot looking past one of those stalks back toward the northwest:


I took that photo because Andrea had notice something interesting in the plant. Here’s a closer view:


It’s a collection of six spherical objects suspended in a loose web; Andrea’s guess was that they were spider egg sacs. Here’s a close-up:


There was one more interesting thing we noticed: Where the stem holding the spheres met the main stalk of the plant, there was a triangular structure that appeared to be made from the same silk as the web. You can see it on the left side of this picture:


Here’s a close-up:


We couldn’t find any spider to go with the putative egg cases, but after I got home I posted photos on, and within 15 minutes Charley Eiseman, co-author of the upcoming book Tracks & Sign of Insects & Other Invertebrates (which I can’t wait to buy) had ID’d the spheres for me. They are indeed the egg cases of a spider, specifically the Bolas spider Mastophora cornigera.

The spider is nocturnal; it hides in plain site during the day by looking exactly like a rounded bird dropping. (When I mentioned that to Andrea, she replied that she actually had noticed what she thought was a bird dropping on the plant not far from the egg sacs. I didn’t notice it at the time, and I can’t find it in any of my photos, unfortunately.)

The spider also has an interesting way of hunting: It dangles a strand of silk with a sticky ball on the end, and swings it with one of its legs to capture flying insects. The ball gives off a scent that mimics moth pheromones, and researchers have found that the spider can vary the scent over the course of an evening to appeal to different moth species that are active at different times of night.

Here’s a segment from David Attenborough’s Life in the Undergrowth showing M. cornigera hunting:

One mystery I still haven’t solved: What was that triangular silk structure at the base of the stem? I tried sending an email to Peter Bryant, a biologist at UC Irvine who has posted some neat photos of Bolas spiders on the web. I wrote him as follows:

I came across what I believe are some Mastophora cornigera egg cases yesterday at the Carpinteria Salt Marsh. I’m curious about one thing, though: There was an odd triangular structure, apparently built out of spider silk, at the point where the stem from which the egg sacs are suspended meets the main stalk of the plant. You can view a photo of the structure in relation to the egg sacs here:

…and a closeup of the triangular structure here:

At first I was thinking the structure might be a hiding place for the spider, but now that I’ve had some help identifying the species, and have looked at the wonderful photos you’ve posted of the adult female, I don’t think that structure would be large enough to hide one (and it doesn’t sound like they go in for that sort of thing, anyway, given their impressive bird-dropping mimicry).

I’m trying to figure out what purpose that structure might have. My lay speculation so far consists of:

* The aforementioned hiding place for the adult spider.
* A structural reinforcement, to prevent the weight of the egg sacs from causing the stem to break off the plant.
* A barrier to help prevent egg-sac predators from traveling from the stalk to the stem.

I’m curious if you know the answer, or would be willing to speculate. Thanks!

Dr. Bryant wrote me back, but unfortunately he didn’t have any ideas about that triangular silk structure. He suggested visiting the location again to see if the spider is nearby, which I’d love to do, but so far I haven’t had a chance (and I’d need to go with Peter, or someone else with official permission to enter that part of the marsh).

More Bolas spider links:

Marsh Mallows

Saturday, October 3rd, 2009


The chaparral mallows (Malacothamnus fasciculatus) were really in bloom at the salt marsh a month or so ago, when I snapped this photo of a particularly attractive set of flowers. There still are a few mallow flowers here and there at the marsh, but lately it’s the coyote brush (Baccharis pilularis) that has been catching my eye. I think it’s interesting how there are male and female coyote brush plants, with each gender having its own, specific kind of flower. I’ll try to get some photos of those the next time I’m at the bluffs or the marsh.